PROVO, Utah (AP) - On the quick bus ride over to the stadium, Taysom Hill leaned back and pictured big holes opening up in front of him.

Nothing this vast, of course. This almost defied imagination.

Hill led a big night on the ground for BYU, rushing for 259 yards - second-most in school history - and three touchdowns to help the Cougars beat up No. 15 Texas 40-21 on Saturday.

The sophomore QB was masterful in guiding the team's new read-option offense as the Cougars (1-1) rolled up 550 yards rushing, eclipsing a 55-year-old team record. It was also the most yards rushing Texas (1-1) has ever allowed, and brought back memories of last season's myriad defensive failures by the Longhorns.

``We expected to, yeah, run on them,'' Hill said. ``But we didn't expect to break the school record. It was working and we were able to move the ball really efficiently on the ground. There was no need to go away from it. So, we didn't.''

The elusive Hill scored on runs of 68, 20 and 26 yards. His 68-yard scamper ties his record for longest by a Cougar QB (he also ran that far against Hawaii last season).

Former BYU luminary Jim McMahon never had a TD run like this. Neither did Steve Young. What's more, Hill's 259 yards rushing were the most by a QB since former Texas great Vince Young had 267 in 2005.

``Anytime that you can be thrown into a category with those guys, it's quite an honor,'' Hill said. ``I feel very honored.''

Hill even came close to breaking BYU's single-game rushing record of 272 yards, a mark set by quarterback Eldon Fortie in 1962. He thinks he could've, too, but coach Bronco Mendenhall told him to take it easy on BYU's final drive of the game, not risk any sort of injury.

Following orders, Hill slid down when defenders got close to him.

``There at the end, there was some opportunities where I could've pulled it and ran,'' Hill said. ``But there was no need and I'm not trying to pad a stat. The only stat I'm trying to get is a win.''

Jamaal Williams had a career-high 182 yards and Paul Lasike added 87 along with a score.

David Ash threw two TD passes to Mike Davis and Joe Bergeron had a short TD for Texas. The Longhorns set a school-record with 715 yards of offense last weekend in a blowout win over New Mexico State. They gained 445 against a stingy BYU defense that was one of the best in the nation last season.

``We didn't get done what we needed to do on either side of the ball,'' Texas coach Mack Brown said. ``We couldn't stop the run ... That's basically the story of the game.''

Well, that and a roughing the punter penalty in the second quarter. Up 14-10, the Longhorns forced BYU to punt, only to have a player slide into punter Scott Arellano. The penalty gave the Cougars a fresh set of downs and they quickly scored to reclaim the lead, which they wouldn't relinquish.

``Big momentum change,'' Texas defensive end Jackson Jeffcoat said.

The teams had to wait out a lengthy weather delay after a storm rolled through the area, complete with a gusty wind and violent rain. When lightning began to flash near the stadium, the kickoff was pushed back 1 hour, 47 minutes.

It's the second straight game BYU had to wait out a lengthy delay.

Hill and the Cougars came out of the locker room ready to go to work, taking the opening drive and marching down the field, before stalling out and settling for a field goal.

He was just warming up. So effective was Hill with his legs that he had 166 yards rushing at halftime.

When Texas tried to focus on the run to start the second half, Hill simply turned to the air, throwing a few down the field to keep the Longhorns honest. He finished 9 of 26 for 129 yards. He also threw an interception.

``When I saw Taysom come out and run like that on the first drive and the way we were moving the ball, I had no doubt we could get the record,'' Williams said.

This after a 19-16 loss at Virginia to open the season, leading the Cougars to shuffle around their offensive line. It seemed to do the trick, paving the way for BYU's rushing attack. The previous record for most yards rushing in a game was 465 against Montana in 1958.

The defense certainly did its part, too, thwarting the Longhorns three times on fourth down in the final quarter.

The loss snapped the Longhorns' streak of 13 straight road wins against nonconference opponents. Texas' speedy Daje Johnson hurt his left ankle in the first half and only had two carries for 4 yards.